ABSTRACT
A detailed study of photovoltaic devices and their response to natural sunlight is difficult since the experimental conditions, i.e. illuminated area, uniformity, spectral stability and distribution of the light source, can be very demanding to reproduce. Conventional laboratory approaches such as varying the intensity of the lamp or using neutral density filters do not provide satisfactory repeatability of the above conditions. Additionally, outdoor characterisation maintains ideal and consistent conditions only within a limited irradiance level. Total irradiance varies during the day between a large range but unfortunately so does the air mass. A rare event such as a solar eclipse combines two remarkable characteristics: the total irradiance varies while the spectral distribution remains virtually the same, and it exhibits an excellent spatial uniformity. These characteristics have been exploited to perform a study on photovoltaic devices and irradiance sensors of different technologies and their relative mismatch.
